Package structure and method of manufacturing the same

ABSTRACT

A method of forming a package structure includes the following steps. A first package structure is formed. The first package structure is connected to a second package structure. The method of forming the first package structure includes the following steps. A redistribution layer (RDL) structure is formed. A die is bonded to the RDL structure. The RDL structure is electrically connected to the die. A through via is formed on the RDL structure and laterally aside the die. An encapsulant is formed to laterally encapsulate the through via and the die. A protection layer is formed over the encapsulant and the die. A cap is formed on the through via and laterally aside the protection layer, wherein the cap has a top surface higher than a top surface of the encapsulant and lower than a top surface of the protection layer. The cap is removed from the first package structure.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of and claims the prioritybenefit of a prior application Ser. No. 16/928,001, filed on Jul. 14,2020. The prior application Ser. No. 16/928,001 is a continuationapplication of and claims the priority benefit of U.S. application Ser.No. 15/806,342, filed on Nov. 8, 2017, now allowed. The entirety of eachof the above-mentioned patent applications is hereby incorporated byreference herein and made a part of this specification.

BACKGROUND

The semiconductor industry has experienced rapid growth due tocontinuous improvements in the integration density of various electroniccomponents (i.e., transistors, diodes, resistors, capacitors, etc.). Forthe most part, this improvement in integration density has come fromcontinuous reductions in minimum feature size, which allows more of thesmaller components to be integrated into a given area. These smallerelectronic components also demand smaller packages that utilize lessarea than previous packages. Some smaller types of packages forsemiconductor components include quad flat packages (QFPs), pin gridarray (PGA) packages, ball grid array (BGA) packages, flip chips (FC),three-dimensional integrated circuits (3DICs), wafer level packages(WLPs), and package on package (PoP) devices and so on.

Currently, integrated fan-out packages are becoming increasingly popularfor their compactness.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A to FIG. 1F are schematic cross-sectional views illustrating amethod of manufacturing a package structure according to a firstembodiment of the disclosure.

FIG. 2A to FIG. 2B are schematic cross-sectional views illustrating amethod of manufacturing a package structure according to someembodiments of the disclosure.

FIG. 3A to FIG. 3H are schematic cross-sectional views illustrating amethod of manufacturing a package structure according to a secondembodiment of the disclosure.

FIG. 4A to FIG. 4C are schematic cross-sectional views illustrating amethod of manufacturing a package structure according to someembodiments of the disclosure.

FIG. 5A to FIG. 5B are schematic cross-sectional views illustrating amethod of manufacturing a package structure according to a thirdembodiment of the disclosure.

FIG. 6A to FIG. 6D are schematic cross-sectional views illustrating amethod of manufacturing a package structure according to a fourthembodiment of the disclosure.

FIG. 7 and FIG. 8 respectively illustrate a PoP device according to someembodiments of the disclosure.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a second feature over or on a first feature in the description thatfollows may include embodiments in which the second and first featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the second and first features,such that the second and first features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath”, “below”, “lower”,“on”, “above”, “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the FIGS. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe FIGS. The apparatus may be otherwise oriented (rotated 90 degrees orat other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

Other features and processes may also be included. For example, testingstructures may be included to aid in the verification testing of the 3Dpackaging or 3DIC devices. The testing structures may include, forexample, test pads formed in a redistribution layer or on a substratethat allows the testing of the 3D packaging or 3DIC, the use of probesand/or probe cards, and the like. The verification testing may beperformed on intermediate structures as well as the final structure.Additionally, the structures and methods disclosed herein may be used inconjunction with testing methodologies that incorporate intermediateverification of known good dies to increase the yield and decreasecosts.

FIG. 1A to FIG. 1F are schematic cross-sectional views illustrating amethod of manufacturing a package structure according to a firstembodiment of the disclosure.

Referring to FIG. 1A, a carrier 10 is provided. The carrier 10 may be aglass carrier, a ceramic carrier, or the like. A de-bonding layer 11 isformed on the carrier 10 by, for example, a spin coating method. In someembodiments, the de-bonding layer 11 may be formed of an adhesive suchas an Ultra-Violet (UV) glue, a Light-to-Heat Conversion (LTHC) glue, orthe like, or other types of adhesives. The de-bonding layer 11 isdecomposable under the heat of light to thereby release the carrier 10from the overlying structures that will be formed in subsequent steps.

A redistribution layer (RDL) structure 12 is formed over the carrier 10and the de-bonding layer 11. In some embodiments, the RDL structure 12includes a plurality of polymer layers PM1, PM2, PM3 and PM4 and aplurality of redistribution layers RDL1, RDL2, RDL3 and RDL4 stackedalternately. The number of the polymer layers or the redistributionlayers is not limited by the disclosure. In some embodiments, the RDLstructure 12 comprises at least three RDL layers. In some embodiments,the RDL structure 12 is free of substrate.

In some embodiments, the redistribution layer RDL1 penetrates throughthe polymer layer PM1, and the bottom surface of the redistributionlayer RDL1 and the bottom surface of the polymer layer PM1 aresubstantially level with each other, and are in contact with thede-bonding layer 11. The redistribution layer RDL2 penetrates throughthe polymer layer PM2 and is electrically connected to theredistribution layer RDL1. The redistribution layer RDL3 penetratesthrough the polymer layer PM3 and is electrically connected to theredistribution layer RDL2. The redistribution layer RDL4 penetratesthrough the polymer layer PM4 and is electrically connected to theredistribution layer RDL3.

In some embodiments, the redistribution layer RDL4 is also referred aspads, and is located in a region for collecting to a die in thesubsequently processes. In some embodiments, the redistribution layerRDL4 protrudes from the top surface of the polymer layer PM4 andexposed, that is, the top surface of the redistribution layer RDL4 ishigher than the top surface of the polymer layer PM4, but the disclosureis not limited thereto. In some other embodiments, the top surface ofthe redistribution layer may be substantially level with the top surfaceof the polymer layer PM4.

In some embodiments, the redistribution layers RDL1, RDL2, RDL3 and RDL4respectively includes a plurality of vias V and a plurality of traces Tconnected to each other. The vias V penetrates through the polymerlayers PM1, PM2, PM3 and PM4 to connect the traces T of theredistribution layers RDL1, RDL1, RDL3 and RDL4, and the traces T arerespectively located on the polymer layers PM1, PM2, PM3 and PM4, andare respectively extending on the top surface of the polymer layers PM1,PM2, PM3 and PM4.

Referring to the enlarged view of the via V and the trace T in FIG. 1A,in some embodiments, the cross-section shape of the via V is invertedtrapezoid, but the disclosure is not limited thereto. In someembodiments, the base angle θ of the via V is an obtuse angle, and thewidth W20 of top surface of the via V is larger than the width W10 ofthe bottom surface of the via V. In some embodiments, the top surface ofthe via V has a larger area than the bottom surface of the via V. Insome other embodiments, the cross-section shape of the via V may besquare or rectangle, and the base angle θ of the via V is a right angle.

In some embodiments, the polymer layers PM1, PM2, PM3 and PM4respectively includes a photo-sensitive material such as polybenzoxazole(PBO), polyimide (PI), benzocyclobutene (BCB), a combination thereof orthe like. The forming methods of the polymer layers PM1, PM2, PM3 andPM4 include suitable fabrication techniques such as spin coating,chemical vapor deposition (CVD), plasma-enhanced chemical vapordeposition (PECVD), lamination or the like. In some embodiments, theredistribution layers RDL1, RDL2, RDL3 and RDL4 respectively includesconductive materials. The conductive material includes metal such ascopper, nickel, titanium, a combination thereof or the like, and isformed by an electroplating process. In some embodiments, theredistribution layers RDL1, RDL2, RDL3 and RDL4 respectively includes aseed layer (not shown) and a metal layer formed thereon (not shown). Theseed layer may be a metal seed layer such as a copper seed layer. Insome embodiments, the seed layer includes a first metal layer such as atitanium layer and a second metal layer such as a copper layer over thefirst metal layer. The metal layer may be copper or other suitablemetals.

Referring to FIG. 1B, a die 17 is placed over and electrically connectedto the RDL structure 12. Specifically, the die 17 is connected to theredistribution layer RDL4 of the RDL structure 12 though a plurality ofconductive bumps 18. The die 17 may be an application-specificintegrated circuit (ASIC) chip, an analog chip, a sensor chip, awireless and radio frequency chip, a voltage regulator chip or a memorychips. The number of the die 17 shown in FIG. 1B is merely forillustration, and the disclosure is not limited thereto. In someembodiments, two or more dies 17 may be mounted onto the RDL structure12, and the two or more dies 17 may be the same types of dies or thedifferent types of dies.

In some embodiments, the die 17 includes a substrate 13, a plurality ofpads 14, a passivation layer 15 and a plurality of connectors 16. Thepads 14 may be a part of an interconnection structure (not shown) andelectrically connected to the integrated circuit devices (not shown) ofthe die 17. The passivation layer 15 covers a portion of the pads 14.The passivation layer 15 includes an insulating material such as siliconoxide, silicon nitride, polymer, or a combination thereof. A portion ofthe pads 14 is exposed by the passivation layer 15 and serves as anexternal connection of the die 17. The connectors 16 are contacted withand electrically connected to the pads 14 not covered by the passivationlayer 15. The connector 16 includes solder bumps, gold bumps, copperbumps, copper posts, copper pillars, or the like.

The die 17 has a first surface 17 a (that is, the top surface) and asecond surface 17 b (that is, the bottom surface) opposite to eachother. In some embodiments, the first surface 17 a is a surface of thesubstrate 13 away from the connectors 16. The second surface 17 b is anactive surface 17 b of the die 17 facing the top surface of the RDLstructure 12, in some embodiments, the second surface 17 b includes aportion of the surface of the connectors 16 and a portion of the surfaceof the passivation layer 15. That is to say, the RDL structure 12 islocated at a front-side (a side close to the connectors 16) of the die17. In some embodiments, the top surface of the via V of the RDLstructure 12 is relatively closer to the second surface 17 b of the die17 than the bottom surface of the via V, and the bottom surface of thevia V of the RDL structure 12 is relatively farther away from the secondsurface 17 b of the die 17 than the top surface of the via V. In otherword, in some embodiments, the top surface of the via V with a largerarea is relatively closer to the active surface 17 b of the die 17 thanthe bottom surface of the via V.

Still referring to FIG. 1B, the conductive bumps 18 are located betweenthe connectors 16 of the die 17 and the redistribution layer RDL4 of theRDL structure 12. In some embodiments, the conductive bumps 18 furthercovers a portion of sidewalls of the connector 16 and a portion ofsidewalls of the RDL4. In some embodiments, the conductive bumps 18 aresolder bumps, silver balls, copper balls, or any other suitable metallicballs. In some embodiments, a soldering flux (not shown) may be appliedonto the conductive bumps 18 for better adhesion. In some embodiments,after the die 17 is connected to the RDL structure 12, an underfilllayer 19 is formed to fill the space between the die 17 and the RDLstructure 12, so as to cover the active surface 17 b of the die 17 and aportion of the top surface of the polymer layer PM4, and surrounds theconnectors 16, the conductive bumps 18 and the redistribution layerRDL4. In some embodiments, the underfill layer 19 further covers aportion of sidewalls of the die 17. In some embodiments, the underfilllayer 19 includes polymer such as epoxy.

Referring to FIG. 1C, an encapsulant 20 is then formed on the RDLstructure 12 to encapsulate the sidewalls of the die 17, the firstsurface 17 a of the die 17 and the sidewalls of the underfill layer 19.In some embodiments, the encapsulant 20 includes a molding compound, amolding underfill, a resin such as epoxy, a combination thereof, or thelike. In some other embodiments, the encapsulant 20 includes aphoto-sensitive material such as PBO, polyimide, BCB, a combinationthereof, or the like, which may be easily patterned by exposure anddevelopment processes or laser drilling process. In alternativeembodiments, the encapsulant 20 includes nitride such as siliconnitride, oxide such as silicon oxide, phosphosilicate glass (PSG),borosilicate glass (BSG), boron-doped phosphosilicate glass (BPSG), acombination thereof, or the like. The encapsulant 20 is formed by asuitable fabrication technique such as spin-coating, lamination,deposition, or similar processes. In some embodiments, the top surfaceof the encapsulant 20 is higher than or over the first surface 17 a ofthe die 17, such that the first surface 17 a of the die 17 isencapsulated by the encapsulant 20. However, the present disclosure isnot limited thereto.

Referring to FIG. 1D, in some embodiments, a protection layer 21 is thenformed over the die 17 and the encapsulant 20. In other words, theprotection layer 21 is a backside film formed at the backside (oppositeto the front-side) of the die 17. In some embodiments, the protectionlayer 21 completely covers the top surface of the encapsulant 20. Insome embodiments, the protection layer 21 is referred as a warpagecontrol layer, and preferably provides a sufficient degree of rigidityto the underlying structure, so as to control the warpage of theunderlying structure. The protection layer 21 may comprise asingle-layer structure or a multi-layer structure. In some embodiments,the protection layer 21 includes an inorganic material, an organicmaterial, or a combination thereof. The inorganic material includessilicon nitride, a low temperature nitride such as aluminum nitride,gallium nitride, aluminum gallium nitride or the like, or a combinationthereof. The organic dielectric material includes a polymer such as PBO,PI, BCB, ajinomoto buildup film (ABF), solder resist film (SR), or thelike, or a combination thereof. However, the present disclosure is notlimited thereto, the protection layer 21 may include any kind ofmaterials, as long as it provides a sufficient degree of rigidity to theunderlying structure against warpage and twisting. The protection layer21 is formed by a suitable fabrication technique such as spin-coating,lamination, chemical vapor deposition (CVD), plasma-enhanced chemicalvapor deposition (PECVD) or the like, for example. In some embodiments,the thickness T1 of the protection layer 21 ranges from 5 μm to 100 μm.

Referring to FIG. 1E, the de-bonding layer 11 is decomposed under theheat of light, and the carrier 10 is then released from the overlyingstructure. In some embodiments, before the carrier 10 is released, aframe tape (not shown) is attached to the protection layer 21, and theframe tape is removed after the carrier 10 is released. Thereafter, theredistribution layer RDL1 is exposed for electrical connection in thesubsequent process. In some embodiments, the redistribution layer RDL1includes a redistribution layer RDL1a and a redistribution layer RDL1b.The redistribution layer RDL1a is also referred as under-ball metallurgy(UBM) layer for ball mounting. The redistribution layer RDL1b may bemicro bump for connecting to an integrated passive device (IPD) 24 inthe subsequent process.

Referring to FIG. 1E and FIG. 1F, a plurality of connectors 23 areformed on and electrically connected to the redistribution layer RDL1aof the RDL structure 12. In some embodiments, the connectors 23 arereferred as conductive terminals. In some embodiments, the connectors 23are, for example, solder balls or ball grid array (BGA) balls. In someembodiments, the material of the connector 23 includes copper, aluminum,lead-free alloys (e.g., gold, tin, silver, aluminum, or copper alloys)or lead alloys (e.g., lead-tin alloys). In some embodiments, theconnectors 23 are placed on the redistribution layer RDL1a by a ballmounting process.

Still referring to FIG. 1F, in some embodiments, an integrated passivedevice (IPD) 24 including a plurality of pads 25 is electricallyconnected to the redistribution layer RDL1b through a plurality ofconductive bumps 26 therebetween. The IPD 24 may be a capacitor, aresistor, an inductor or the like, or a combination thereof. The IPD 24is optionally connected to the RDL structure 12, and the number of theIPD 24 is not limited to that is shown in FIG. 1F, but may be adjustedaccording to the design of the product. An underfill layer 27 is formedto fill the space between the IPD 24 and the RDL structure 12. Theunderfill layer 27 covers a portion of the surface of the IPD 24 and aportion of the bottom surface of the RDL structure 12, and surrounds thepads 15 of the IPD 24 and the conductive bumps 26. The material of theunderfill layer 27 is similar to that of the underfill layer 19, whichis not described again.

Still referring to FIG. 1F, a package structure 50 a is thus completed.The package structure 50 a includes the die 17, the encapsulant 20, theRDL structure 12, the connectors 23, the IPD 24 and the protection layer21. The connectors 23 and the IPD 24 are electrically connected to thedie 17 through the RDL structure 12. The protection layer 21 is formedfor controlling the warpage of the package structure 50 a, that is, theprotection layer 21 provides a sufficient degree of rigidity to thepackage structure 50 a against warpage and twisting. Thereafter, thepackage structure 50 a may be connected to other package components suchas a printed circuit board (PCB), a flex PCB, or the like through theconnectors 23.

In the package structure 50 a, the encapsulant 20 encapsulates thesidewalls and the first surface 17 a of the die 17. However, the presentdisclosure is not limited thereto.

Referring to FIG. 2A, processes similar to those of FIGS. 1A to 1C areperformed, in some embodiments, after the encapsulant 20 is formed asshown in FIG. 1C, a grinding or polishing process such as a chemicalmechanical polishing (CMP) process is performed to remove a portion ofthe encapsulant 20, such that the first surface 17 a of the die 17 isexposed, and an encapsulant 20 a encapsulating the sidewalls of the die17 is formed. In some embodiments, the top surface of the encapsulant 20a is substantially coplanar with the first surface 17 a of the die 17.

Referring to FIG. 2B, after the encapsulant 20 a is formed, processessimilar to those of FIG. 1D to FIG. 1F are performed subsequently, so asto form a package structure 50 b. The package structure 50 b differsfrom the package structure 50 a in that the top surface of theencapsulant 20 a is substantially level with the first surface 17 a ofthe die 17, and the protection layer 21 is in contact with the topsurface of the encapsulant 20 a and the first surface 17 a of the die17. In some embodiments, the protection layer 21 completely covers thetop surface of the encapsulant 20 a and the first surface 17 a of thedie 17. The other structural characteristics of the package structure 50b are similar to those of the package structure 50 a, which is notdescribed again.

FIG. 3A to FIG. 3H are schematic cross-sectional views illustrating amethod of manufacturing a package structure according to a secondembodiment of the disclosure. The second embodiments differs from thefirst embodiment in that, a plurality of through integrated fan-out vias(TIVs) 28 are formed aside the die 17.

Referring to FIG. 3A, similar to the processes of FIGS. 2A and 2B, a RDLstructure 12 including polymer layers PM1, PM2, PM3, PM4 andredistribution layers RDL1, RDL2, RDL3, RDL4 is formed over a carrier10. In some embodiments, the redistribution layer RDL4 includes aredistribution layer RDL4a and a redistribution layer RDL4b. Theredistribution layer RDL4b is located aside and around theredistribution layer RDL4a. A die 17 is placed on and electricallyconnected to the redistribution layer RDL4a through a plurality ofconductive bumps 18. An underfill layer 19 is formed to fill the spacebetween the die 17 and the RDL structure 12. The structuralcharacteristics of the die 17, the RDL structure 12, the conductivebumps 18 and the underfill layer 19 are similar to those of the firstembodiments, which will not be described again.

A plurality of TIVs 28 are formed on and electrically connected to theredistribution layer RDL4b. In some embodiments, the TIVs 28 includecopper, nickel, solder, alloys thereof, or the like. In someembodiments, the TIV 28 includes a seed layer and a conductive layerformed thereon (not shown). The seed layer is, for example, a titaniumor/and copper composited layer. The conductive layer is, for example, acopper layer. An exemplary forming method of the TIVs 28 includesforming a photoresist layer such as a dry film resist over the carrier10. Thereafter, openings are formed in the photoresist layer, theopenings exposes a portion of the top surface of the redistributionlayer RDL4b, and the TIVs 28 are then formed in the openings byelectroplating. In some other embodiments, the TIVs 28 further include abarrier layer (not shown) under the seed layer to prevent metaldiffusion. The material of the barrier layer includes, for instance,metal nitride such as titanium nitride, tantalum nitride, or acombination thereof.

Still referring to FIG. 3A, the die 17 is located between and surroundedby the TIVs 28, that is, the TIVs 28 are aside or around the die 17. Insome embodiments, the top surface of the TIV 28 is higher than the firstsurface 17 a of the die 17, but the disclosure is not limited thereto.In some other embodiments, the top surface of the TIV 28 issubstantially level with the first surface 17 a of the die 17.

Referring to FIG. 3B, an encapsulant 20 is formed over the RDL structure12, so as to encapsulate the sidewalls of the TIVs 28, the sidewalls anda portion of a surface of the RDL4b, the sidewalls of the underfilllayer 19, the sidewalls and the first surface 17 a of the die 17. Thematerial of the encapsulant 20 is substantially the same as that of thefirst embodiment. The encapsulant 20 may be formed by forming anencapsulant material layer over the carrier 10. The encapsulant materiallayer encapsulates the top surfaces and sidewalls of the die 17 and theTIVs 28. Thereafter, a grinding or polishing process is performed toremove a portion of the encapsulant material layer, such that the topsurfaces of the TIVs 28 are exposed. In some embodiments, the topsurfaces of the TIVs 28 and the top surface of the encapsulant 20 aresubstantially coplanar and higher than or over the first surface 17 a ofthe die 17, but the present disclosure is not limited thereto.

Referring to FIG. 3B and FIG. 3C, a protection layer 21 is then formedover the die 17, the encapsulant 20 and the TIVs 28. In someembodiments, the protection layer 21 is referred as a warpage controllayer. The material and the forming method of the protection layer 21are similar to those of the first embodiments.

Referring to FIG. 3C and FIG. 3D, a portion of the protection layer 21is removed to form a plurality of openings 29. The removal methodincludes exposure and development processes, laser drilling process,photolithography and etching processes, or a combination thereof. Theopening 29 penetrates through the protection layer 21 to expose aportion of the top surface of the TIV 28. The opening 29 is alsoreferred as a recess.

Still referring to FIG. 3D, thereafter, a plurality of caps 30 areformed in the openings 29 and on the TIVs 28. In some embodiments, thecaps 30 are formed for protecting the TIVs 28 from oxidation orpollution. The cap 30 includes metal, organic material, or a combinationthereof. In some embodiments, the cap 30 includes solder, solder pasteadhesive or a combination thereof, and the cap 30 may be formed bydropping solder balls in the openings 29 and then a reflow process isperformed. In some other embodiments, the cap 30 includes an organicmaterial, such as an organic solderability preservative (OSP), and thecap 30 is referred as an OSP layer, such as a copper OSP layer. In someembodiments, the OSP layer includes benzotriazole, benzimidazoles, orcombinations and derivatives thereof. In some embodiments, the OSP layeris formed by coating, and the OSP coating is applied by immersing thesurfaces of the TIVs 28 exposed in the openings 29 in an OSP solution,or spaying an OSP solution on the surfaces of the TIVs 28 exposed in theopenings 29. The OSP solution may contain alkylimidazole, benzotriazole,rosin, rosin esters, or benzimidazole compounds. Alternatively, the OSPcoating is made with phenylimidazole or other imidazole compoundsincluding 2-arylimidazole as the active ingredient.

In some embodiments, the cap 30 is formed within the opening 29, and thetop surface of the cap 30 is lower than the top surface of theprotection layer 21, but the disclosure is not limited thereto. In someother embodiments, the cap 30 may filled up the opening 29 and protrudesfrom the top surface of the protection layer 21. The cross-section shapeof the cap 30 may be inverted trapezoid, inverted trapezoid with a arcedbase, square, rectangle, semicircular, or any other shape, as long asthe cap 30 covers the TIV 28 to protect the TIV 28 from oxidation.

Referring to FIG. 3E and FIG. 3F, processes similar to FIG. 1E and FIG.1F are performed, so as to form a package structure 50 c. The de-bondinglayer 11 is decomposed under the heat of light, and the carrier 10 isthen released from the overlying structure. Thereafter, a plurality ofconnectors 23 are formed on and electrically connected to theredistribution layer RDL1a of the RDL structure 12. An IPD 24 iselectrically connected to the redistribution layer RDL1b through aplurality of conductive bumps 26.

Referring to FIG. 3F, the package structure 50 c is thus completed. Thepackage structure 50 c includes the die 17, the encapsulant 20, the TIVs28, the RDL structure 12, the connectors 23, the IPD 24 and theprotection layer 21. The protection layer 21 covers and contacts withthe top surface of the encapsulant 20, and a portion of the top surfaceof the TIVs 28. The protection layer 21 has a plurality of openings 29exposing the TIVs 28, and a plurality of caps 30 are located in theopenings 29 to protect the TIVs 28 from oxidation or pollution. That isto say, a portion of the top surface of the TIV 28 is covered by theprotection layer 21, and another portion of the top surface of the TIV28 is covered by the cap 30.

Referring to FIG. 3G and FIG. 3H, in some embodiments, the packagestructure 50 c is further connected to a package structure 60 to form apackage-on-package (PoP) device 70 a.

Referring to FIG. 3G, the package structure 60 is provided. The packagestructure 60 may be any kind of package structures according to thefunctional demand of the PoP device 70 a. In some embodiments, thepackage structure 60 includes a package body 61 and a plurality ofconnectors 62 attached to the package body 61. In some embodiments, theconnectors 62 are referred as conductive terminals. The material and theforming method of the connector 62 are similar to those of the connector23 of the package structure 50 c. In some embodiments, the connectors 62are located at the positions corresponding to the positons of theopenings 29 of the package structure 50 c.

Referring to FIG. 3G and FIG. 3H, a reflow process is performed at leaston the connectors 62, so that a connector 62 a is formed to connect thepackage structure 50 c and the package structure 60. The connectors 62 aare in electrical contact with the TIVs 28. In some embodiments in whichthe cap 30 is formed of solder, solder paste adhesive or a combinationthereof, the cap 30 is melted and fused with the connector 62 during thereflow process, that is, the connector 62 a is formed of the connector62 and the cap 30. In some embodiments in which the cap 30 is an OSPlayer, before the reflow process is performed, a cleaning process isperformed to remove the cap 30, that is, the connector 62 a is formed ofthe connector 62.

Referring to FIG. 3H, in some embodiments, an underfill layer 63 isfurther formed to fill the space between the package structure 50 c andthe package structure 60 and surround the connectors 62 a. The PoPdevice 70 a including the package structure 50 c and the packagestructure 60 is thus completed, and the package structure 50 c and thepackage structure 60 are connected through the connectors 62 a. The PoPdevice 70 a as shown in FIG. 3H is just for illustration, and thedisclosure is not limited thereto.

Referring to FIG. 3B, FIG. 4A and FIG. 4B, in some other embodiments,after the encapsulant 20 is formed as shown in FIG. 3B, the grinding orpolishing process is performed, such that the top surfaces of the TIVs28 and the first surface 17 a of the die 17 are exposed, and anencapsulant 20 a is formed. In some embodiments in which the TIVs 28 areformed with a top surface higher than the first surface 17 a of the die17, a portion of the encapsulant 20 and a portion of the TIVs 28 areremoved during the grinding or polishing process. In some embodiments inwhich the TIVs 28 are formed with a top surface substantially level withthe first surface 17 a of the die 17, a portion of the encapsulant 20 isremoved during the grinding or polishing process. In some embodiments,the top surfaces of the TIVs 28, the top surface of the encapsulant 20 aand the first surface 17 a of the die are substantially coplanar witheach other. In other words, the protection layer 21 is in contact withthe first surface 17 a of the die 17, the top surface of the TIVs 28,and the top surface of the encapsulant 20 a. In some embodiments, theprotection layer 21 completely covers the first surface 17 a of the die17, the top surface of the TIVs 28, and the top surface of theencapsulant 20 a.

Referring to FIG. 4B, a package structure 50 d is then formed throughthe processes similar to those of FIG. 3C to FIG. 3F.

Referring to FIG. 3F and FIG. 4B, the package structure 50 d differsfrom the package structure 50 c in that the top surfaces of the TIVs 28,the top surface of the encapsulant 20 a and the first surface 17 a ofthe die 17 are coplanar with each other, and the protection layer 21 isin contact with the first surface 17 a of the die 17. Other structuralcharacteristics of the package structure 50 d are similar to those ofthe package structure 50 c. Similarly, the package structure 50 d mayfurther connected to other package structures to form a PoP device.

Referring to FIG. 4B and FIG. 4C, processes similar to those of FIG. 3Gto FIG. 3H are performed, such that the package structure 50 d isconnected to a package structure 60, and a PoP device 70 b is formed.

FIG. 5A to FIG. 5B are schematic cross-sectional views illustrating amethod of manufacturing a package structure according to a thirdembodiment of the disclosure. The third embodiment differs from theforegoing embodiments in that a protection layer 121 is formed at theback side of the die 17. In some embodiments, the protection layer 121acts as a warpage control layer and a heat spreader.

Referring to FIG. 2A and FIG. 5A, in some embodiments, after theencapsulant 20 a is formed aside the die 17, the top surface of theencapsulant 20 a and the first surface 17 a of the die 17 form a surface31. A protection layer 121 is attached to the surface 31 through anadhesive layer 32. The adhesive layer 32 is in contact with the die 17and the encapsulant 20 a. In some embodiments, the protection layer 121is a plate or a sheet, and acts as a warpage control layer forpreventing or reducing the warpage of the underlying structure, and alsoact as a heat spreader conducting heat away from the die 17. In someembodiments, the adhesive layer 32 may also help to conduct heat awayfrom the die 17.

The protection layer 121 may include single material or compositematerial, and may be a single-layer structure or a multi-layerstructure. In some embodiments, the protection layer 121 includes athermally conductive material, and has a thermal conductivity greaterthan the die 17 and the encapsulant 20 a. In some embodiments, theprotection layer 121 includes a conductive material and is floating,that is to say, the protection layer 121 is not electrically connectedto any other layers. In some embodiments, the protection layer 121includes a rigid metal (such as copper, steel, or a combinationthereof), a ceramic material, a silicon containing material, diamond, ora combination thereof. In some embodiments, the protection layer 121 isa copper layer, a steel layer, or a diamond film. In some otherembodiments, the protection layer 121 includes a composite materialcomposed of a matrix material and fillers. In some embodiments, thematrix material includes graphite, graphene, a polymer or a combinationthereof. The fillers include diamond, oxide such as aluminum oxide orsilicon oxide, carbide such as silicon carbide, or a combinationthereof. However, the material of the protection layer 121 is notlimited to those described above, the protection layer 121 may includeany material, as long as the protection layer 121 preferably provides asufficient degree of rigidity to present or reduce the warpage of theunderlying structure and also effectively conducts heat away from thedie 17.

In some embodiments, the adhesive layer 32 includes a die attach film(DAF), a thermal interface material (TIM), or a combination thereof. Insome embodiments, the material of the adhesive layer 32 is alsothermally conductive, and has a thermal conductivity greater than thedie 17 and the encapsulant 20 a. In some embodiments, the thermalconductivity of the adhesive layer 32 and the thermal conductivity ofthe protection layer 121 may be the same or different. In someembodiments, the thermal conductivity of the adhesive layer 32 may begreater or less than the thermal conductivity of the protection layer121.

Still referring to FIG. 5A, in some embodiments, the thickness T2 of theprotection layer 121 ranges from 30 μm to 400 μm. The thickness T2 ofthe protection layer 121 is dependent on the material thereof. In someembodiments in which the protection layer 121 is a diamond film, thethickness T2 of the protection layer 121 may be less than 30 μm. In someembodiments, the width W1 of the protection layer 121 is substantiallythe same as the width W2 of the surface 31. The first surface 17 a ofthe die 17 and the top surface of the encapsulant 20 a are covered bythe protection layer 121. In some embodiments, the first surface 17 a ofthe die 17 and the top surface of the encapsulant 20 a are completelycovered by the protection layer 121. In some other embodiments, thewidth W1 of the protection layer 121 is less than the width W2 of thesurface 31, and greater than the width W3 of the die 17. That is, thefirst surface 17 a of the die 17 and a portion of the top surface of theencapsulant 20 a are covered by the protection layer 121. In yetalternative embodiments, the width W1 of the protection layer 121 may besubstantially the same as or slightly less than the width W3 of thefirst surface 17 a of the die 17, thus the first surface 17 a of the die17 is covered or partially covered by the protection layer 121. That isto say, the thickness T2 and the width W1 of the protection layer 121may be adjusted, as long as the protection layer 121 provides theproperties necessary to achieve the objectives of the presentdisclosure.

Referring to FIG. 5A and FIG. 5B, thereafter, processes similar to thoseof FIG. 1E to FIG. 1F are performed, such that the carrier 10 isreleased with the de-bonding layer 11 decomposed under the heat oflight. Thereafter, a plurality of connectors 23 are electricallyconnected to the redistribution layer RDL1a of the RDL structure 12. AnIPD 24 is electrically connected to the redistribution layer RDL1bthrough a plurality of conductive bumps 26.

Referring to FIG. 5B, a package structure 50 e is thus completed. Thepackage structure 50 e includes the die 17, the encapsulant 20 a, theRDL structure 12, the connectors 23, the IPD 24, and the protectionlayer 121. In some embodiments, the protection layer 121 is used forcontrolling the warpage of the package structure 50 e and for spreadingthe heat of the die 17. The other structural characteristics are similarto those of the package structure 50 b.

FIG. 6A to FIG. 6D are schematic cross-sectional views illustrating amethod of manufacturing a package structure according to a fourthembodiment of the disclosure. The forth embodiment differs from thethird embodiment in that a plurality of TIVs 28 are formed aside the die17.

Referring to FIG. 6A, after the TIVs 28 and the encapsulant 20 a isformed aside the die 17 (as shown in FIG. 4A), a protection layer 121 isattached to the die 17 and the encapsulant 20 a through an adhesivelayer 32. In some embodiments, the protection layer 121 covers the firstsurface 17 a of the die 17 and a portion of the top surface of theencapsulant 20 a. The TIVs 28 are not covered by the protection layer121, and exposed. In some other embodiments, the protection layer 121only covers or partially covers the first surface 17 a of the die 17,and does not cover the top surface of the encapsulant 20 a and the TIV28. The material of the protection layer 121 and the material of theadhesive layer 32 are substantially the same as those of the thirdembodiment.

Referring to FIG. 6A and FIG. 6B, a plurality of caps 30 are formed onthe TIVs 28 to at least cover the top surfaces of the TIVs 28. In someembodiments, the top surface of the TIV 28 is completely covered by thecap 30. In some embodiments, the top surface of the TIV 28 and a portionof the top surface of the encapsulant 20 a are covered by the cap 30.The material, forming method and the properties of the cap 30 aresimilar to those of the second embodiment. In some embodiments, thecross-section shape of the cap 30 may be semicircular, arc-shaped,square, rectangle, trapezoid, or a combination thereof. The cap 30 maybe any shape, as long as the TIV 28 is covered and protected fromoxidation or pollution.

Still referring to FIG. 6A and FIG. 6B, the carrier 10 is released withthe de-bonding layer 11 decomposed under the heat of light. Thereafter,a plurality of connectors 23 are electrically connected to theredistribution layer RDL1a of the RDL structure 12. An IPD 24 iselectrically connected to the redistribution layer RDL1b through aplurality of conductive bumps 26.

Referring to FIG. 6B, a package structure 50 f is thus completed. Thepackage structure 50 f includes the die 17, the encapsulant 20 a, theTIVs 28, the RDL structure 12, the connectors 23, the IPD 24 and theprotection layer 121. The TIVs 28 are covered by the caps 30. In someembodiments, the TIVs 28 are covered to be protected from oxidation orpollution. In some embodiments, the protection layer 121 is used forcontrolling the warpage of the package structure 50 f and spreading theheat of the die 17. The package structure 50 f may further coupled toother package structures to form a PoP device.

Referring to FIG. 6C and FIG. 6D, in some embodiments, a packagestructure 60 including a package body 61 and a plurality of connectors62 is provided, thereafter a reflow process is performed, such that aconnector 62 a is formed to connect the package structure 50 f and thepackage structure 60. Similar to the second embodiments, the connector62 a may be formed of the connector 62 or formed of the connector 62 andthe cap 30, the forming method of the connector 62 a is similar to thatof the second embodiment as shown in FIG. 3G to FIG. 3H.

Thereafter, an underfill layer 63 is formed to fill the space betweenthe package structure 50 f and the package structure 60, and a PoPdevice 70 c is thus completed.

In the second and the fourth embodiments, as shown in FIG. 3H, FIG. 4Cand FIG. 6D, the package structure 50 c/50 d/50 f is connected to thepackage structure 60, so as to form a PoP device 70 a/70 b/70 c,however, the number of the package structures that may be coupled to thepackage structure 50 c/50 d/50 f is not limited thereto. In some otherembodiments, more than one package structures are connected to thepackage structure 50 c/50 d/50 f, and IPDs may also be coupled to thepackage structure 50 c/50 d/50 f. For the sake of brevity, the packagestructure 50 c is taken for example.

Referring to FIG. 7 , in some embodiments, a PoP device 70 d comprisinga package structure 50 c, a package structure 61 and a package structure64 is formed. The package structure 50 c includes a plurality of TIVs28. The TIVs 28 includes a plurality of TIVs 28 a and a plurality ofTIVs 28 b. The TIVs 28 a are aside and around the die 17. The TIVs 28 bare aside the TIVs 28 a and relatively farther away from the die 17 thanthe TIVs 28 a, that is to say, no die is surrounded by the TIVs 28 b,but the disclosure is not limited thereto.

Still referring to FIG. 7 , the package structure 61 is electricallycoupled to the package structure 50 c through the connectors 62 a. Apackage structure 64 is electrically coupled to the package structure 50c though the connectors 65 by a similar method as described in theprocesses of FIG. 3G to FIG. 3H. The package structure 61 and thepackage structure 64 may be the same types or different types of packagestructures. The package structure 61 is connected to the TIVs 28 a ofthe package structure 50 c, and the package structure 64 is connected tothe TIVs 28 b of the package structure 50 c.

Referring to FIG. 8 , in some embodiments, besides the package structure61 and the package structure 64 are coupled to the package structure 50c, an IPD 66 is further electrically coupled to the package structure 50c through a plurality of connectors 67, and a PoP device 70 e is thuscompleted. The IPD 66 may be a capacitor, a resistor, an inductor or thelike, or a combination thereof. In some embodiments, the TIVs 28includes a plurality of TIVs 28 c between the TIVs 28 a and the TIVs 28b. The package structure 61 is connected to the TIVs 28 a. In someembodiments, the package structure 64 is connected to the TIVs 28 b. TheIPD 66 is connected to the TIVs 28 c. The IPD 66 is located between thepackage structure 61 and the package structure 64, but the disclosure isnot limited thereto.

In the present disclosure, a protection layer is formed at the backsideof the die. In some embodiments, the protection layer acts as a warpagecontrol layer to control warpage of the package structure. In someembodiments, the protection layer also acts as a heat spreader of thedie.

In accordance with some embodiments of the disclosure, a packagestructure includes a die, a TIV, an encapsulant, a RDL structure, anunderfill layer, a protection layer, and a cap. The TIV is aside thedie. The encapsulant laterally encapsulates the die and the TIV. The RDLstructure is electrically connected to the die. The underfill layer isdisposed between the die and the RDL structure and laterallyencapsulated by the encapsulant. The protection layer is overlying thedie and the encapsulant. The cap covers a top surface of the TIV andlaterally aside the protection layer. A top surface of the cap is higherthan a top surface of the encapsulant and lower than a top surface ofthe protection layer.

In accordance with some embodiments of the disclosure, a packagestructure includes a RDL structure, a die, a TIV, an encapsulant, awarpage controlling layer and a cap. The die is electrically bonded tothe RDL structure through a plurality of conductive bumps. The TIV isaside the die and landing on a top conductive RDL of the RDL structure.The encapsulant encapsulates sidewalls of the die, the TIV and the topconductive RDL. The warpage controlling layer covers the die and theencapsulant. The cap is laterally aside the warpage controlling layerand covers the TIV. A top surface of the cap is located at a levelheight between a top surface of the encapsulant and a top surface of thewarpage controlling layer.

In accordance with some embodiments of the disclosure, a method offorming a package structure includes the following processes. A firstpackage structure is formed by the following processes: forming a RDLstructure; electrically bonding a die to the RDL structure; forming aTIV on the RDL structure and laterally aside the die; forming anencapsulant to laterally encapsulate the TIV and the die; forming aprotection layer over the encapsulant and the die; and forming a cap onthe TIV and laterally aside the protection layer. The cap is removedfrom the first package structure, and the first package structure isconnected to the second package structure.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the disclosure.Those skilled in the art should appreciate that they may readily use thedisclosure as a basis for designing or modifying other processes andstructures for carrying out the same purposes and/or achieving the sameadvantages of the embodiments introduced herein. Those skilled in theart should also realize that such equivalent constructions do not departfrom the spirit and scope of the disclosure, and that they may makevarious changes, substitutions, and alterations herein without departingfrom the spirit and scope of the disclosure.

What is claimed is:
 1. A method of forming a package structure,comprising: forming a first package structure, comprising: forming aredistribution layer (RDL) structure; bonding a die to the RDLstructure, wherein the RDL structure is electrically connected to thedie; forming a through via on the RDL structure and laterally aside thedie; forming an encapsulant to laterally encapsulate the through via andthe die; forming a protection layer over the encapsulant and the die;and forming a cap on the through via and laterally aside the protectionlayer, wherein the cap has a top surface higher than a top surface ofthe encapsulant and lower than a top surface of the protection layer;removing the cap from the first package structure; and connecting thefirst package structure to a second package structure.
 2. The method ofclaim 1, wherein the connecting the first package structure to thesecond package structure comprises: electrically connecting a conductiveterminal of the second package structure to the through via of the firstpackage structure.
 3. The method of claim 1, wherein the cap is formedto cover a top surface of the through via.
 4. The method of claim 1,wherein the forming the cap comprises: removing a portion of theprotection layer to expose at least a portion of a top surface of thethrough via; and forming an organic solderability preservative (OSP)layer on the through via exposed by the protection layer, wherein theOSP layer serves as the cap.
 5. The method of claim 4, wherein theforming the OSP layer comprises: immersing the at least the portion ofthe top surface of the through via in an OSP solation.
 6. The method ofclaim 4, wherein the forming the OSP layer comprises: spaying an OSPsolution on the at least the portion of the top surface of the throughvia.
 7. The method of claim 1, wherein the encapsulant is formed tofurther cover a top surface of the die, and the protection layer isseparated from the die by the encapsulant therebetween.
 8. The method ofclaim 7, further comprising removing a portion of the encapsulantcovering the top surface of the die so that the die is exposed, and theprotection layer is formed in contact with the die.
 9. A method offorming a package structure, comprising: forming a through via laterallyaside a die; forming an encapsulant to laterally encapsulate the throughvia and the die; forming a warpage controlling layer covering theencapsulant and the die; forming a cap laterally aside the warpagecontrolling layer and on the through via, wherein the cap has a topsurface higher than a top surface of the encapsulant and lower than atop surface of the warpage controlling layer; removing the cap; andconnecting a component to the through via.
 10. The method of claim 9,further comprising: bonding the die to a RDL structure.
 11. The methodof claim 9, further comprising: forming an adhesive layer between thewarpage controlling layer and the die.
 12. The method of claim 11,wherein the forming the warpage controlling layer comprising: forming aconductive layer on the adhesive layer.
 13. The method of claim 11,wherein the forming the warpage controlling layer and the forming theadhesive layer comprises forming a warpage controlling material and anadhesive material have thermal conductivities greater than a thermalconductivity of the die.
 14. The method of claim 9, wherein the formingthe cap comprises forming a cap material having a thermal conductivitygreater than a thermal conductivity of the die.
 15. The method of claim9, wherein the cap is formed to contact the warpage controlling layer,and the through via is completely covered by the warpage controllinglayer and the cap.
 16. The method of claim 9, wherein the cap is formedso that the cap is spaced apart from the warpage controlling layer, andthe through via is completely covered by the cap.